The following verses in the Old Testament all relate to God's call for His people to be a holy people. I offer them for your meditation and study. Lord willing I will eventually expound on them. I trust you will find the progression of God's revelation instructive.
Exo 19:6 - and you shall be to Me a kingdom of priests and a holy nation.' These are the words that you shall speak to the sons of Israel."
Exo 22:31 - "You shall be holy men to Me, therefore you shall not eat [any] flesh torn to pieces in the field; you shall throw it to the dogs.
Lev 10:10 - and so as to make a distinction between the holy and the profane, and between the unclean and the clean,
Lev 11:44 - 'For I am the LORD your God. Consecrate yourselves therefore, and be holy, for I am holy. And you shall not make yourselves unclean with any of the swarming things that swarm on the earth.
Lev 11:45 - 'For I am the LORD who brought you up from the land of Egypt to be your God; thus you shall be holy, for I am holy.'"
Lev 19:2 - "Speak to all the congregation of the sons of Israel and say to them, 'You shall be holy, for I the LORD your God am holy.
Lev 20:7 - 'You shall consecrate yourselves therefore and be holy, for I am the LORD your God.
Lev 20:26 - 'Thus you are to be holy to Me, for I the LORD am holy; and I have set you apart from the peoples to be Mine.
Num 15:40 - so that you may remember to do all My commandments and be holy to your God.
Num 16:3 - They assembled together against Moses and Aaron, and said to them, "You have gone far enough, for all the congregation are holy, every one of them, and the LORD is in their midst; so why do you exalt yourselves above the assembly of the LORD?"
Num 16:5 - and he spoke to Korah and all his company, saying, "Tomorrow morning the LORD will show who is His, and who is holy, and will bring [him] near to Himself; even the one whom He will choose, He will bring near to Himself.
Num 16:7 - and put fire in them, and lay incense upon them in the presence of the LORD tomorrow; and the man whom the LORD chooses [shall be] the one who is holy. You have gone far enough, you sons of Levi!"
Deu 7:6 - "For you are a holy people to the LORD your God; the LORD your God has chosen you to be a people for His own possession out of all the peoples who are on the face of the earth.
Deu 14:2 - "For you are a holy people to the LORD your God, and the LORD has chosen you to be a people for His own possession out of all the peoples who are on the face of the earth.
Deu 14:21 - "You shall not eat anything which dies [of itself.] You may give it to the alien who is in your town, so that he may eat it, or you may sell it to a foreigner, for you are a holy people to the LORD your God. You shall not boil a young goat in its mother's milk.
Deu 28:9 - "The LORD will establish you as a holy people to Himself, as He swore to you, if you keep the commandments of the LORD your God and walk in His ways.
Deu 33:3 - "Indeed, He loves the people; All Your holy ones are in Your hand, And they followed in Your steps; [Everyone] receives of Your words.
1Sa 21:5 - David answered the priest and said to him, "Surely women have been kept from us as previously when I set out and the vessels of the young men were holy, though it was an ordinary journey; how much more then today will their vessels [be holy?]"
2Ch 31:18 - The genealogical enrollment [included] all their little children, their wives, their sons and their daughters, for the whole assembly, for they consecrated themselves faithfully in holiness.
2Ki 4:9 - She said to her husband, "Behold now, I perceive that this is a holy man of God passing by us continually.
Job 5:1 - "Call now, is there anyone who will answer you? And to which of the holy ones will you turn?
Job 15:15 - "Behold, He puts no trust in His holy ones, And the heavens are not pure in His sight;
Psa 89:5 - The heavens will praise Your wonders, O LORD; Your faithfulness also in the assembly of the holy ones.
Psa 89:7 - A God greatly feared in the council of the holy ones, And awesome above all those who are around Him?
Isa 4:3 - It will come about that he who is left in Zion and remains in Jerusalem will be called holy--everyone who is recorded for life in Jerusalem.
Isa 6:13 - "Yet there will be a tenth portion in it, And it will again be [subject] to burning, Like a terebinth or an oak Whose stump remains when it is felled. The holy seed is its stump."
Isa 63:18 - Your holy people possessed Your sanctuary for a little while, Our adversaries have trodden [it] down.
Jer 2:3 - "Israel was holy to the LORD, The first of His harvest. All who ate of it became guilty; Evil came upon them," declares the LORD.'"
Eze 44:19 - "When they go out into the outer court, into the outer court to the people, they shall put off their garments in which they have been ministering and lay them in the holy chambers; then they shall put on other garments so that they will not transmit holiness to the people with their garments.
Eze 44:23 - "Moreover, they shall teach My people [the] [difference] between the holy and the profane, and cause them to discern between the unclean and the clean.
Eze 46:20 - He said to me, "This is the place where the priests shall boil the guilt offering and the sin offering [and] where they shall bake the grain offering, in order that they may not bring [them] out into the outer court to transmit holiness to the people."
Dan 4:8 - "But finally Daniel came in before me, whose name is Belteshazzar according to the name of my god, and in whom is a spirit of the holy gods; and I related the dream to him, [saying,]
Dan 4:9 - 'O Belteshazzar, chief of the magicians, since I know that a spirit of the holy gods is in you and no mystery baffles you, tell [me] the visions of my dream which I have seen, along with its interpretation.
Dan 4:18 - 'This is the dream [which] I, King Nebuchadnezzar, have seen. Now you, Belteshazzar, tell [me] its interpretation, inasmuch as none of the wise men of my kingdom is able to make known to me the interpretation; but you are able, for a spirit of the holy gods is in you.'
Dan 5:11 - "There is a man in your kingdom in whom is a spirit of the holy gods; and in the days of your father, illumination, insight and wisdom like the wisdom of the gods were found in him. And King Nebuchadnezzar, your father, your father the king, appointed him chief of the magicians, conjurers, Chaldeans [and] diviners.
Dan 8:24 - "His power will be mighty, but not by his [own] power, And he will destroy to an extraordinary degree And prosper and perform [his will;] He will destroy mighty men and the holy people.
Dan 12:7 - I heard the man dressed in linen, who was above the waters of the river, as he raised his right hand and his left toward heaven, and swore by Him who lives forever that it would be for a time, times, and half [a] [time;] and as soon as they finish shattering the power of the holy people, all these [events] will be completed.